Investigation of flow cytometric (FCM) analysis of urinary bladder barbotage specimens has demonstrated that FCM is useful and practical for monitoring recurrences and response to therapy in bladder carcinoma patients. We believe, however, that before this technology is offered on a nationwide basis, it is essential to optimize and standardize it, taking into account recent cytometric innovations and, especially, advances in the understanding of neoplastic and preneoplastic diseases of the urinary bladder. First, we will develop a method to detect a wider range of urologic neoplasia, particularly low grade papillary and flat preneoplastic lesions without detectable ploidy abnormalities. Potentially, our approach will correct some of the most serious technical drawbacks associated with the current cytochemistry and instrumentation, including unsuitability for fixed cells or cells recovered from voided urine, low resolution and sensitivity for abnormal DNA stemlines, high nonspecific staining of certain cell types, and lack of widespread laboratory acceptance of the technique. We propose to develop a method which will employ simple, widely acceptable cytochemistry and a standard commercially available instrument. However, to determine the optimal combination of cellular parameters for our method, we will also perform sophisticated multiparameter analysis directly comparing three or more fluorescence parameters on the same cells. Finally, our studies will improve the scientific basis of FCM studies by comparing FCM with cytogenetics on the same patients and defining the cellular abnormalities detectable by FCM which are characteristic of the full range of preneoplastic bladder lesions.